Extra 400 Wiki
Welcome to the Extra 400 Wiki This is the platform for consolidating and sharing our knowledge about the Extra 400 and 500 aircraft. We are a closed community, meaning that we do not intend to open this wiki to the public. Rather, we want to be able to share the knowledge without fear of creating negative impact to the market value or marketability of our aircraft or causing unwelcome intervention by FAA or EASA. The site is targeted at owners, operators, pilots as well as technical people working on these aircraft. It is also open to select suppliers of parts and services. Main menu Flying Should you be flying an Extra 400? The Extra 400 is a complex, high performance pressurized aircraft. While its performance and features make it extremely enticing, you as the pilot need to be fully aware of the fact that it is a demanding aircraft. If you intend to fly an Extra 400, you should be: * experienced and current enough ( 500 hours total and 50 hours latest year as a minimum) * a very good "stick and rudder" pilot * an experienced IFR pilot (at least 100 hours) * be familiar with the operation of engines in the 300 HP power range. * be technically interested with above average understanding of aircraft and engine operations. If your skills cover all of the above, you should be OK flying the Extra 400. Keep in mind that this is an orphaned aircraft which was not completely developed at the time production stopped. As a result, there are some quirks that must be mastered. Thorough transition training is necessary and you are encouraged not to skimp on recurring training. Advice on basic operations Known issues and precautions Turbine Inlet Temperature limitations The POH states a redline limit of 1750 F. This is considered excessive by several knowledgeable people and consensus is that 1650F should be used instead. Economy Cruise settings SN 03 had the so called "balanced flow injectors" from Continental installed. It nevertheless failed the GAMI test so that GAMI injectors were subsequently ordered and installed. GAMI knew exactly about the issue. The injectors set they provided were off-the-shelf items that effectively cured the balancing issue. SN03 is now capable of smooth Lean of Peak operations down to about 70 F LOP. Unfortunately, it is not possible to do so without TIT exceeding the 1650 F limit. As a result, SN03 is not being operated Lean of Peak. As an alternative, the following economy cruise settings have been found to provide a reasonable performance/fuel flow combination while keeping TIT in check: * MP: 26.5 inches * RPM: 2270 * Fuel flow: 67 liters per hour (17.5 GPH) * TIT: 1650 F * Airspeed at FL180 / ISA day: 180 KTAS Incident reports and lessons learned Turbo to intercooler duct disconnect At least three occurences of this incident have been identified. The duct that connects the turbo to the intercooler comes lose in flight. Depending upon altitude at the time of the event, this is perceived as a more or less explosive engine stoppage with subsequent loss of cabin pressurization. Depending upon altitude the engine may completely stop producing power due to excessively rich mixture. Propeller windmills. The cause of this is that it is extremely difficult to reassemble the lower cowling to the aircraft while simultaneously slotting the intercooler into its lower supporting rail. The resulting tension in the short ducting between turbo and intercooler can force the silicon duct out of the metal end parts. * It is advisable to carefully watch this issue when re-assembling. * Pilots should always have emergency oxygen ready for use when operating above FL120. * In the case of SN03, the incident happened at FL190. An emergency descent to FL100 was conducted and the engine restarted more or less by itself at this altitude. Performance reports Ownership List of aircraft The Extra factory reportedly built 26 aircraft before shutting down production. Three aircraft have been dismantled or accidentally lost. These are SN 01 - factory prototype . There are photos showing its airframe being used in ultimate load testing SN 02 - crashed just after delivery with one casualty. Accident report in German here. SN 08 - emergency landed on water in Norway following an engine fire. No casualties. aircraft wreck has been offered for sale for some time and then vanished. List of serial numbers and registration history here. Insurance Maintenance List of knowledgeable companies / Individuals In Europe, Flugzeugwerft Möller located at the airfield of Bonn Hangelar EDKB in Germany have several Extra 400s under maintenance. The CEO, Martin Birkmann is a former Extra factory employee and has personal connections to people there which can prove invaluable for troubleshooting. Flugzeugwerft Möller have performed several panel upgrades and one full aircraft rebuild (SN03 N121AG). In the USA... Maintenance Manual Illustrations Best Practices Known Issues and Fixes Parts sourcing Modifications and projects Extended exhaust Early production aircraft had a very short exhaust tube. This causes major staining downwind from this point and is also suspected to be the cause of damage to O-rings of the landing gear hydraulic shock absorber. More recent aircraft have a small extension (about 1 inch / 3 cm) added. Some owners have had this extended even further and reported that it cured the staining issue. Scimitar blade propeller For N-reg aircraft there exists a Form 337 modification for the propeller to use "b" shaped blades from MT. These seem to provide a significant performance boost. We should verify this by collecting performance data points from planes with the a and b type blades. The new blades can also be ordered with a very expensive full leading edge protection. This is well worth the expense as it eliminates a weakness of the MT blades. Garmin G500 Garmin GTN 650 and 750 JPI EDM 930 Engine conversion to air cooling Redesign of cooling system and lower cowling = Latest activity T-Tail in the sunset. Photo by Timo S. Category:Browse